Work machine

Abstract

This work machine comprises: a telescoping actuator that moves a first boom with respect to a second boom; an electrical drive source that is disposed in a movable portion of the telescoping actuator; a first biasing mechanism that maintains the connection state between the telescoping actuator and the first boom; a first connection mechanism that switches the connection state between the telescoping actuator and the first boom on the basis of the power of the electrical drive source; a second biasing mechanism that maintains the connection state between the first boom and the second boom; a second connection mechanism that switches the connection state between the first boom and the second boom on the basis of the power of the electrical drive source; and a clutch that discretionally intermittently transmits the power of the electrical drive source to the first connection mechanism and the second connection mechanism.

The invention claimed is: 
     
       1. A work machine comprising:
 a telescopic boom having a first boom and a second boom that are telescopically overlapped; 
 a telescoping actuator that moves the first boom in a telescoping direction with respect to the second boom; 
 an electrical drive source provided in a movable portion of the telescoping actuator; 
 a first fixing pin that connects the telescoping actuator and the first boom; 
 a first biasing mechanism that biases the first fixing pin to maintain a connection state between the telescoping actuator and the first boom; 
 a first connection mechanism that operates on the basis of the power of the electrical drive source, the first connection mechanism switching between the connection state and a disconnection state between the telescoping actuator and the first boom by inserting and removing the first fixing pin; 
 a second fixing pin that connects the first boom and the second boom; 
 a second biasing mechanism that biases the second fixing pin to maintain a connection state between the first boom and the second boom; 
 a second connection mechanism that operates on the basis of the power of the electrical drive source, the second connection mechanism switching between the connection state and a disconnection state between the first boom and the second boom by inserting and removing the second fixing pin; and 
 a clutch that is disposed in a power transmission path from the electrical drive source to the first connection mechanism and the second connection mechanism, the clutch discretionally intermittently transmitting the power of the electrical drive source to the first connection mechanism and the second connection mechanism. 
 
     
     
       2. The work machine according to  claim 1 , wherein the clutch cuts off the power of the electrical drive source at least when the first fixing pin is restored by biasing force of the first biasing mechanism and/or when the second fixing pin is restored by biasing force of the second biasing mechanism. 
     
     
       3. The work machine according to  claim 1 , further comprising a speed reducer that decelerates a driving speed of the electrical drive source and outputs the decelerated driving speed, wherein
 the clutch is disposed between the electrical drive source and the speed reducer. 
 
     
     
       4. The work machine according to  claim 1 , wherein the clutch includes an electromagnetic clutch, a mechanical clutch, or a torque diode.